Yes but IIRC, textbook drawings of atoms usually look nothing like the physical reality (since simplified drawings never show the electrons forming a cloud around the nucleus and greatly shrink the scale of the distance between the electrons and nucleus for simplicity). So it's not surprising that we would expect the physical reality vs. the drawings of the molecules to be very different too.

Maybe it was a long exposure (relative to the speed of electrons!)? So even though it's empty space most of the time, the long enough exposure catches the electrons in every part of the path of the bond.

Well, TFA says they measured the repulsive force caused by Pauli exclusion principle. That means that their microscope was sensible to filled orbitals, not electrons.

Anyway, you can't really take a picture of an electron bounded into an atom. The uncertainty principle makes it impossible so say exactly where around the atom the electron is. The only way to measure that is releasing the electron from its bound, and then, it says nothing about where it was just before you release it.

The other reason you can't take a picture of an electron is because photons of light are larger than the thing you are trying to image. Also you misquoted the uncertainly principle. It says you CAN find the precise location of an electron, but not its momentum. Or vice-versa find its momentum, but not position.

Not exactly. If the electron is bounded, it has some specific momentum probabilities, and some specific position probabilities. You can't find its position with any different certainty unless you remove it from the bounded state.

And that comes from the uncertainty principle. It is not just Dx * Dp >= h/(2 * pi). It is an statement that each state has some specific uncertanty, and that it isn't lower than that relation.

Wrong again. The uncertainty principle is very badly named because it applies even if you know *everything* about the electrons and are uncertain about nothing.

The problem is like trying to find the position and frequency of a wave packet. Both position and frequency are kind of macro quantities and it wouldn't make sense to fix them both at the same time. For example a wave with only one frequency must be the same everywhere and hence has no position. Conversely a delta function has an infinitely wide spectrum.

So if the Pantacene is made of Benzene and the Benzene is C6H6, what is that gray flat smooth material that the molecules are sitting on top of in the second picture? Is this simply due to a focus so incredibly tuned that you can't see past the Pentacene molecules? I would expect that to be a field of bumps and crazy random shapes because it has to be made of some molecule or atom, right? How would they finish the slide/table/surface of that so accurately? I'm used to seeing that when you see bacteria or viruses with an electron microscope, what is in effect here that we don't see an alien landscape back-dropping these molecules? I'm not calling into question the authenticity of the image, just curious if anyone knows.

An AFM image will often look like it has a shadow. In that case, the tip was probably scanning from the right, and it "bounced" after being raised by the pentacene. The shadow size is related to the tip speed as much as the molecule height.

You are correct. I get the chance to see AFM readouts at work (you see some really cool shit in a fab), and this is a bit higher resolution that I'm used to seeing, but the "shadow" is something you'll frequently see.

Yes, I'm sure you PhD in molecular physics and your extensive experience with AFM allows you to make such propositions. Perhaps you should contact your colleges and let them in on your ground breaking realization~

I think he wants you to check the surety of your conclusions. You stated that you "called into question" the results, and supported that with an observation, but the observation was easily explained by someone with basic knowledge of the thing you were questioning. So, since you knew that you were ignorant of this topic, but went ahead and drew a wrong conclusion, and did in fact question the veracity of the results, the person responded to you with mockery.

Sure, you are allowed to use your eyes and draw conclusions. And when your conclusions are proffered with gusto, and are totally wrong, and based on ignorance, then you are open for a little criticism.

This image isn't from an electron microscope, it uses AFM (atomic force microscopy: http://en.wikipedia.org/wiki/Atomic_force_microscope), which actually touches the molecules with its tip. In this case though, they bonded a single carbon monoxoide molecule to the AFM cantilever so that it would only interact with the oxygen atoms on the pentacene molecule. I imagine it didn't image the substrate at all because of that

This image isn't from an electron microscope, it uses AFM (atomic force microscopy: http://en.wikipedia.org/wiki/Atomic_force_microscope [wikipedia.org]), which actually touches the molecules with its tip. In this case though, they bonded a single carbon monoxoide molecule to the AFM cantilever so that it would only interact with the oxygen atoms on the pentacene molecule. I imagine it didn't image the substrate at all because of that

It doesn't actually touch the molecules, because weak force cancels out the attraction. That's kind of a key point here because touching it was too destructive to get these images in the first place.

A lot of microscopy like this will be done using very carefully prepared atomically smooth surfaces [omicron.de]. A good example would be Cu(111) [ibm.com].
I haven't' dug in, but they might also work with something akin to the "depth of field" in optical work to largely exclude the effect of the background.

So if the Pantacene is made of Benzene and the Benzene is C6H6, what is that gray flat smooth material that the molecules are sitting on top of in the second picture? Is this simply due to a focus so incredibly tuned that you can't see past the Pentacene molecules? I would expect that to be a field of bumps and crazy random shapes because it has to be made of some molecule or atom, right? How would they finish the slide/table/surface of that so accurately? I'm used to seeing that when you see bacteria or viruses with an electron microscope, what is in effect here that we don't see an alien landscape back-dropping these molecules? I'm not calling into question the authenticity of the image, just curious if anyone knows.

From the paper: "In this work, we present atomically resolved AFM measurements of pentacene both on a Cu(111) substrate and on a NaCl insulating film. For atomic resolution with the AFM, it is necessary to operate in the short-range regime of forces, where chemical interactions give substantial contributions."

This was a scanning probe microscope, and the tip of the probe was a single carbon monoxide atom. Apparently the CO didn't interact with the Cu or NaCl in such a way that it saw contrast from atom to atom, but it had a finer interaction with the atoms in the pentacene.

Sorry to reply to myself, but here's the most important reason for the lack of substrate heterogeneity in the image:

"The AFM images (Fig. 1, C and D) were recorded in constant-height mode; that is, the tip was scanned without z feedback parallel to the surface while the frequency shift {Delta}f was being recorded (16). In this and all of the following measurements, the tip height z is always given with respect to the STM set point over the substrate."

In school, when I ran AFM I allow feedback from the tip to adjust the height of the probe so that it maintains contact with the thing I'm imaging, regardless of topography. Here, they had a very smooth substrate and then set the height of their probe to a fixed position above it.

Also the physioelectronic structure of the cu(111) is diffuse enough such that you can't easily resolve individual atoms. Each copper atom is so heavily bonded to it's neighbor that there is very little difference from one atom to the next. If you think about it, that makes sense since copper is a conductor, so the electrons must be able to move from one atom to the next easily. Graphite on the other hand (polymerized carbon like the pentacene here) is an insulator -- much less overlap between the orbitals of neighboring atoms.

Clearly this is a fraud perpretrated by a fanatical intro to chemistry teacher.

Seriously though, maybe they cleaned up the background noise or maybe the tip (which they modified with carbon monoxide so it was "tuned") was extremely selective in how it responded to the substrate material.

It's interesting to see how the electrons bunch up at the ends. The aromatic delocalization clearly equalizes the energy levels of the bonds, making the entire molecule behave like a conductor, and concentrate charge at the extremes. Just as in a metal, electrons loosely float in the conduction band, it looks they do the same in pentacene, illustrating why graphite is such a good conductor.

I fail to see the novelty of this, it's another little incremental improvement in AFM resulution. They were able to image benzene rings with AFM 20 years ago; I remember in grad school one of the guys showing a video of them actually making a lot of substituted rings rearrange their layers on command, like a row of soldiers.

It's a basic tenant of cosmology that the universe looks pretty much the same in all directions. If there really was a big empty spot that would be a very interesting finding.

The location of the Hubble deep field was chosen because of the lack of nearby, bright objects. There are many objects in the HDF that are bright enough to be accessible to professional optical telescopes, quite a few that are within reach of some of the larger amateur telescopes and radio surveys had revealed all kinds of stuff, pre

The pic, here [flickr.com], with the foil on the microscope made me smile. The whole damn thing is cool but that there is foil too I felt like if I just could get a glimpse of some duct tape somewhere we could even show this to non-geeks and make them smile too.

For example with 3D electron microscopy. It requires multiple copies of the same molecule on a chilled plate, take a progressive electron microscopy scan of the plate, and the 3D image is reconstructed from the multiple images. Individual atoms can often be identified by relative size. It's been awhile since I've looked at this but I can only assume the field has progressed since then.

So, does this mean for all those years when we see a modelled structure of a molecule, it has been theory as one has never been observed?
So now, theory has been proven and is now science as it has now been observed?

Theory is not fact until it has been proven by science. Science, where something can be observed, repeated and gives the same/similar outcome every time. That's what I understand theory and science as.

Science never proves anything. It only gives better and better probability that a particular theory accurately reflects reality. Or at least can predict observations.

Measuring the distribution of forces across a molecule with an atomic force microscope is certainly a valuable observation and I'm sure the technique will help refine and test theories of molecular arrangement, but it isn't "proof" and it doesn't suddenly make anything "true."

A hypothesis becomes a theory when some one comes up with a tested that could prove it false.

This is why you need a falsifiable test to be considered a scientific theory* to begin with.By that, I mean a test that could show the hypothesis is false.

So my hypothesis may be, all object fall at the same rate.My first falsifiable test might be to go to the top of Piza, and drop two objects with different mass. An observer at the bottom jots down which hit the ground first.Then the test can be refined. For examp

The marking in Hz is most probably referred to the vibration of the cantilever (see how an AFM works), while the other unit is not Amps but Angstrom (1Å = 0.1nm). The pentacene molecule is long roughly 17Å.
This stuff is on another planet of cool.

Symmetrical, IIRC... but I don't think that has much to do with this. Geekoid's thinking is more along my line of reasoning, esp. after some of the explanations people have given of how AFM scanning works.

Maybe it's based on a base line? so, for examples, if your baseling was 10Hz, -1Hz would be 9.

Now that doesn't seem to make sens at the number sI am using, but when dealing with the number you would be using to do this, it makes more sens the a 8 decimal place number.Also, it my be a standard defined unit, not 1 Hz.So a uit might by in.00001 Hz.or 12345423 Hz.

Thanks. Hmm, yeah, I suppose your average Joe wouldn't have the slightest bit of interest in knowing those details, but "News for Nerds" certainly would be expected to give more technical specifics than news targeted to your average Joe...

Also, they could'a used a clearer font or something. That Å looks just like a regular uppercase A. (Of course, it's not much better in this font...)

The summary and the linked article are misleading. This is not the "first time a single molecule has been imaged." It's the first time a single molecule has been imaged using AFM. Scanning tunneling microscopy (STM) has been used for about a decade now to image single molecules. Just a simple google image search [google.com] will show you lots of them. My favorite is this guy [jmtour.com] who is imaging something he's calling "nanocars" which are single molecules. These finding are in no way less impressive due to resolution th

The funny thing is that the first person to deduce this (Friedrich August Kekulé von Stradonitz) realized the solution to the problem of structure, after having a dream in which a snake bit its own tail.

Wow, this is amazing. It looks much like what I'd expect from high school chemistry all those years ago:)

Watson and Crick wouldn't have had that much trouble with DNA if they had these tools... will the IBM scientists be able to do this for more complex molecules? As a complete layman in Chemistry, I think I recall that there are lots of work that involve the spatial geometry of molecules.

I likely would have had this post up about 20 earlier, but I've just managed to pick myself off the floor after taking a look at the photo. As a chemist, I personally find the verification of theory a significant milestone in our understanding. It's one thing to have a theory, and then through somewhat serendipitous means, verify the theory, but to have an actual photo, brings it to a new level.

Greg

Yes, I do have a life outside the lab, but maybe not as much of one as I once thought.

I am not a nuclear physicist so maybe my question is understandable...

I thought that when you get to the molecular level The uncertainty principle would start to take effect. Very large molecules like DNA might be observable but what about smaller molecules? At what size scale would the uncertainty principle make observation impossible?

The Heisenberg uncertainty principle applies at the quantum level and its effect becomes more pronounced as the sizes of the objects and systems decrease. However, this alone imposes no limit on observability.

Put simply, the principle states that the more precisely you know the position of a particle the less precisely you can know its momentum (and therefore velocity). At the quantum level the observation necessarily perturbs the system being observed.

In other news, the International Olympic Committee has filed a trademark infringement suit against IBM and God, showing that pentacine resembles the trademarked "interlocking five ring [fredlaw.com]" design of the Olympic Games.

45nm is 450 angstrom, so you can see by the 20 angstrom ruler in one of the pictures that chip design is getting pretty small. In fact, you can see the atoms lined up in the traces of chips!http://i.zdnet.com/blogs/afm-bpm-e-beam.jpg

We take this model for granted. It's one thing for a handy, convenient model to hold Balls in place with sticks and the you connect your large blue Oxygen balls to the tiny Red hydrogen balls and call it a model.

It's quite another that it's the actual, physical representation of it.

We look at atoms and imagine electron shells -- that's really a domain that electrons spend their time in.

However, physicists currently have this model of particles being particles. Now if a solid, frozen substance under the head of a pin, however, is detecting the structures of "most common region of covalent bonding" as actual "stick like" structures -- when in all rights, the interference of the probe should be pushing the electron around it -- then maybe we need to rethink this concept of particles.

>> My own belief, and I'm likely to get slammed for this on Slashdot by folks who think about physics and chemistry all day -- is that EVERYTHING is a field. Particles are fields with pinpoint connections to other dimensions and that exhibit mass. But what you would expect, from a field, touching a field, is that the "domains" of the electron bonding, would appear solid.

If you really think about it, the electron and proton in these pictures are so small, that the distance from the electron is as far from the proton vs. its size, that it would be like a period on this sentence on a football field.

THAT any of these molecules is solid, means that the potential fields where the electron COULD BE, have some disruption on space, and that the patterns of force of the probe, interfere with the patterns of force on the studied atom.

If Atoms were really very tiny particles, we would SOMETIMES see a structure and sometimes not -- because the probe's electron and the sampled atom's electron would not be occupying the same location most of the time.

>> It's a bit like asking the basic question: Why are things opaque and why are they solid? Fields themselves are the only things that could be stopping the probe. And if physics recognizes the "strong and weak force" -- are those really propagated by particles, or is it a disturbance in space itself. I'm one of the anachronisms who still believes in the aether, I suppose -- think of Dark Matter, as the New Aether.

However, physicists currently have this model of particles being particles. Now if a solid, frozen substance under the head of a pin, however, is detecting the structures of "most common region of covalent bonding" as actual "stick like" structures -- when in all rights, the interference of the probe should be pushing the electron around it -- then maybe we need to rethink this concept of particles.

My own belief, and I'm likely to get slammed for this on Slashdot by folks who think about physics and chemist

In a follow-up session, the Zurich researchers announced that by this time next year, they hope to have imaged two molecules. "We won't stop there," said one scientist, "We plan to image ten, then a thousand, and so on until we are able to image an entire piece of, say, fairy-cake."

Thanks to specialised microscopes, we have long been able to see the beauty of single atoms. But strange though it might seem, imaging larger molecules at the same level of detail has not been possible â" atoms are robust enough to withstand existing tools, but the structures of molecules are not. Now researchers at IBM have come up with a way to do it.

It's not that the molecule itself needs to be big enough, it's the structure of it. The stuff holding it together. The stuff holding the molecule together could not withstand the instruments, but now they've developed a way to do it.